The overall objective of this study is to validate a stool assay system based on ummmunodetection of the neoplasm-derived colonocyte markers, Ag 33.28 and MUC-1, which have been shown immunohistochemically to highly discriminate colorectal neoplasia from normal mucosal. Should the colonocyte marker assays outperform fecal blood tests, evaluation of their application in the general screening and in various surveillance settings would be strongly supported.